Architect Bernard Tschumi often finds creative solutions to challenging assignments, in buildings that preserve, protect and fit their locations.

Tschumi showed some of his unique work in cities around the world to Cornell architecture students in a public lecture, "Concept-Form and Topo-Types," April 17 in Lewis Auditorium, Goldwin Smith Hall.

"It's been rare to see someone with such a clear and radical approach to architecture education and practice," said College of Architecture, Art and Planning Dean Mohsen Mostafavi in introducing Tschumi, dean of the Graduate School of Architecture, Planning and Preservation at Columbia University from 1988 to 2003.

As a theorist and the author of "The Manhattan Transcripts" and "Architecture and Disjunction," Tschumi "helped people rethink the very nature of architectural institutions and the city," Mostafavi said.

Tschumi discussed his process as a cross-application of context, content and concept, and showed a series of "doubles," similar design solutions to two different projects, using materials and forms specific to each project's needs.

"If that concept is the same two times, is the building the same both times?" he asked.

For large auditoriums in Rouen and Limoges, Tschumi employed a rounded double-envelope form for each. One concert hall had a metal shell surrounding a concrete interior, with transparent plastic seating; the other was built in a forest, inspiring the architect's first use of wood; in this case, he used wooden seats, staircases and other interior elements and a polycarbonate outer shell.

Tschumi made it clear he was less interested in form than in finding creative solutions to a project -- "to do things that do not belong to the realm of clichés of architecture."

When he was asked to design a 10 million-square-foot housing project in Beijing, Tschumi said he was concerned about a recent wave of high-rise construction destroying the social fabric of many areas of the city. His solution was to build the housing project on pillars, to preserve the existing neighborhood.

"The way in which architecture is commissioned, we rarely choose the site and rarely choose the program," he said. "Most of the time, I take advantage of the site [or the program]. They give you so many square feet -- they are always very precise about it, but never tell you how to get there. They don't care -- you're free."

Tschumi also showed two projects he undertook on very challenging sites -- an athletic center at the University of Cincinnati, which he squeezed between a stadium and other existing facilities; and his current project, the New Acropolis Museum in Athens, built just 800 feet from the Parthenon.

"How do you design a museum across from the most influential building in Western civilization without touching any of this?" he said.

The triangular building contains friezes, statuary and other artifacts from the Acropolis, which is in full view from the glass-enclosed third floor; and museum visitors can also look down through glass floors at the activity directly below the building -- it rests on pillars over a working archaeological site, which Tschumi said was the best location for the museum. The result is "a building as much about the history of the site as the artifacts inside."